Method of typographic printing



Feb. 21, 1961 D. J. BI-IERNARDI METHOD OF TYPOGRAPHIC PRINTING Filed Nov. 25, 1955 United States Pate-1 1:0

' 'METHOD OFTYPOG'RAPHIC P" a Dominic J. Bernardi, Scarsdale,N :Y., assignor'toln'ter chemical Corporation; New York, N.Y., a corporation of Ohio Filed Nov. 25, 1955, Ser. No. 549, 203

4 Claims. (Cl. 101-426) This invention relates to "the a of typographic printing with inks which'dry by absorption of moisture, and

aims remake possible high speed web" printing with inks solvent. '-The-- inks--dry -by--absorbing--waterfrom the' stock; theair --or from -steam--or -waterdirected-at'the printed surface; the water j absorbed qby the .ink separates the resin from the solvent-water combination, which is rapidly absorbed by the stock. "Such inks set much more rapidly than conventional linseeddoil inks, and they can 'bei-formulated to be substantially nonodoro ushence de rahi ity or. pr ntin ood. pac a es 5 Certaimdiflicultiesare.encountered, in printingmoisture their ext.end,cd distribution. systems; N with diiierenees; iin

tordinarymambient conditions, ,anink .whic distributes and prints one day will not do so another da when the relative humidityis substantially higher. :It as been necessetting ..inks. on "conventional. typographic presses, :with w sary, in order to produce satisfactoryinks, to build in resistance to the higher humidities-encountered. This in ..,t urn. slows up the ink dry. Even inks formulated for the lowest normal humidity ranges (rto bev printable pp sto 55% relawanumiaity 'will not 'dry'stifficientlyjjfast enough in 'inul'tipl'e films "toperiiiit web printing 'inexcess j of about 300' to 400 feet per minute, unlessbackrwaxing or sprayingof the web to'pfev'nt offset is resorted to. And for most printingplants,- =inks must be formulated to be printable up to'80 to '90%- felative hurnidityfsothat they cannot be dried at speeds in exeess of :about 200 often not print "fine half-tones a t' higher humidities, it

has been found desirable to abstain fromeXces'sii/e detail on plates used for printing ordinary-moisturefsettinginks.

Inks based on glycols also have certain'advantages: whenjdesigned to be dried by heat alone, and are used to some extent in the, high speed printing'fof publications.

'But such inks lhave ha'd to be formulated to besubstantially insensitive to moisturepinordemto ensure proper feet per minute. Fur'ther'more; because these-inks will "web leaves the enclosure.

printability, and hence are.essentially-heatsdryinginlcs,

making no use of -thegmoisture' precipitation principle in -their drying I twould obviously be advantageous tol'fmaintain the press-room at relatively lowdconstan t humidity, so that inks wouldnot be subjectedto the vagaries" 'f-Ka-mbient humidity changes. But the cost otco'ntrolledidehumidification is ".so. highas to .oiitwe ight the advantages; Fu'r thermora'ifthe press-room 1slmaintained,a't,a elatively .1w. r a ve ll i ihfli Parak eth r "ice - 2 out, and-this causes later difii'culties in printingan'd processing. v V I have discovered'how to bothgimprove printability and increase the drying speed'of moisture setting inks in press rooms where thexambient humidity varies over wide limits. In accordance with my invention, I maintain about the distribution system of a typographic press with an extended distribution system, a body of air with a relative humidity below the relative humidity of the press room in general, and in. no event above 50%. If desired, the airmay be additionally saturated with sufficient solvent vapor to retard evaporation of ink so1vent,.a's disclosed in the Gessler et al. application Serial No. 421,- 242; filed April 6,1954, to permit the use of a very volatile glycol, andtheprintedweb passed into a heater, preferably charged with super-heated steam, to dry the webrapidlya g I. have furthermore di'scovered thatif inks are used in my method whichare not printable at relative humidities above the 50-55% range, at 9 F., then the prints can be 'di'iedfatpress speeds or, 1000 feet per minute and higher. in an. ordinary super-heated steam drier, with the suiprisin resuitofa ,three fold or greater increase in speed over conventional practice, as compared with a .r'ather small change in the humidity range at which the ,ihk's areprintable. V

The invention can best -be-understoo=d by reference to the drawing, which shows schematically a four color-press i equippedfor. the practice of my invention.

-The press comprises 4 separate. units of substantially identical design, identified in the drawing by :the color .which is-brdinarily:printedbythe unit; Each unit cons'ists of a'printing cylinder 10 havinga printing plate mounted on it, and an impression cylinder 11. 'A web .12 o f paperis fed through the press by appropriate roll- .ers,..preferab1y passing after printing into a conventional super. heated steam drier toset the inkbya combination of moistureandheatr d Each plate is inked; by. a distributing system which comprises a series of rollers operating betweemthe foun- Itairf13 and .the plate. The metal fountain roller 14 takes his from the fountain, and transfers it to arubber ductor roller-. 15, to a metalroller 16, to a rubber roller; 17, thence to the oscillating metal-ink storage roller- 18 .which ;ar1.be-water:cooled.v A rubber idler roller 19, take-sthe ink,f.t;o..the final stages of the distributingsystem,contact- ,ing the form, roller21 which'inks the plateand contacts the metal roller 20; roller 20' is in contact with distributfingmoller 22 andfform'roller 24; the water cooled metal "roller23 inks boththe form rollers 24 and 25. k .l The entire; press structure is surrounded by an enclosure 26, preferably of some material such as glass, iLuciti or other transparent material; this enclosure *is complete except for "a slit 27 through which the -w'eb 'enters'the. enclosure, and a slit28 through which the The enclosure is provided with appropriate hatches and doors so that,- for example, a-pressman can get at any fountain from thettop of the press,':or so: that ,thepre'ss can be criteredf'romtheys'ide forlthe purpose 10f changing plates and soon: -A ir is run into theaenclosure through amanifold--29, having portsfitl distributed, about the enclosure :so. jtl'1 at dilution with-fresh air, brought in by the web 12, is kept "at a minimum. The air is drawmfrom. an 'inlet pipe dl ..-.through a column 43 ofldesiccant (for example, ;a fiv e llfoot column packed with anhydrous calcium, chloride fbrio uettes and flakes) through a blower..,t7]and,a,batile chamber-48 into the manifold 29.

The blower} 47 can. be an:ordinaryblowen lbntiifi idesired to use dry aircontained ink solvent vapor ?-?-:i 41 q na ts prs asi iss at .yi a d 31, operating in a liquid seal 32 of solvent. To pass from the inlet ports 33 to the outlet ports 34, the dry air fed into the compressor must pass through the liquid solvent, and thus it becomes substantially completely saturated with solvent vapor at the temperature and pressure in the compressor chamber.

For operation with systems which'use solvent-saturated dehydrated air, means must be provided for determining the dew point of the solvent in the enclosure. For example, a water cooled etched or ground mirror 36, with a temperature indicator 37, can be observed. As soon as its reflectivity increases on account of condensed vapor, the mirror loses its frosted appearance and the dew point temperature can then be read off on the temperature indicator. Mos-t preferably, a photo-electric system for indicating the first increase in reflectivity (the dew point) is used in combination with a resistance thermometer or a sensitive thermocouple, attached to the surface of the mirror. All readings can be made on instruments outside the enclosure.

1 also provide temperature measuring devices 40 at one or more strategic points in the distributing system. These are connected, by electrical leads, to registering devices outside of the press enclosure where the temperature can be read accurately. The registering devices are also, preferably, connected to controls which automatically keep the temperature of the rollers within a predetermined range. As shown in the drawings, these devices 40 may be mounted on the large oscillated water cooled roller 18, known in this particular distributing system as the ink storage roller.

Because I use dried air, it is possible to control the necessary relationship of solvent concentration in the special atmosphere to the vapor pressure of the solvent in'the inks being distributed by cooling the rollers, without running the risk that water will be precipitated out of the air onto the rollers.

In the practiceof my invention, I haveused conventional water setting inks.

These inks comprise pigments dispersed in varnishes which are solution of resins in glycols and/or polyglycols, using resins with high watertolerance, e.g. unesterified rosin maleic acid adducts.

Such links are generally printable, without any addants,

up to. about 65 to 70% relative humidity at 75 F. In

conventional practice, these inks are formulated with addants-such as triethanolamine, or other materials to give more water tolerance-so as to be printable up to '80 to 90% relative humidity at 75 F., depending on climatic conditions. The addants used affect the drying rate, cause some pigments to change color, and may adversely affect film properties. By using my invention, it is possible to use conventional maleated-rosin glycol inks without any addants, without regard to ambient conditions.

By using the combination ofdried air saturated with solvent vapor, it is possible to use the conventional -maleated-rosin vehicles in glycols which evaporate relatively rapidly, such as ethylene and propylene glycols.

the paper is sufiiciently weakened in the drying process to cause substantial difliculties.

Ihave discovered that it ispossible to produce inks which, when printed in dried air alone, according to" the present invention, can be dried at speeds up ,to 1000 feet per minute with ordinary superheated steam driers. Such inks are disclosed and claimed in my copending patent application SerialNo. 549,202, filed November'2'5, 1955. *Theseinks are not" printable beyond 50 'to 55% relative humidity at 75 F. A typical satisfactory set of four color inks can be made as follows:

EXAMPLE 1.VARNISH Parts by weight Amberol 750 (partial glycerol ester of maleated rosin) Diethylene glycol The resin is melted, and dissolved in the solvent.

This ink was of fairly heavy body, measuring 19.4 on an inkometerrun at 1200 r.p.m.

Second down BED INK OF SECD Parts by weight Varnish of Example 1 60.2 Diethylene glycol 17.1 Lithol red 9.5 Clay 1.9 Watchung red 11.3

This ink measured 16.8 on the inkometer.

Third down BDUE INK 0F SET Parts by weight Varnish of Example 1 56.0 Diethylene glycol 14.7 Clay V 23.4 Bronze blue 5.0 Victoria blue 0.9 This ink measured 12.0 on the inkometer.

' Fourth down BLACK INK 0F SE1- Parts by weight Varnish of Example 1 61.3

Diethylene glycol 22.6 Carbon black 12.0 Bronze blue 4.1

This ink measured 7.8 on the inkometer.

While these inkshave other advantages than drying speeds, as compared with conventional moisture setting inks, they make possible for the first time the attainment of very high press speeds in the typographic printing of food packages, such as bread wrappers and the like.

It is interesting to note. that these inks, formulated with relatively non-volatilepolyglycols and water-sensitive resins, can be dried on super-heated steam driers at speeds of the order of 1000 feet per minute in multiple films whereas inks made from conventional resins used in moisture settinginks, with the volatile simple glycols, can only be dried in similar multiple films at speeds of the order of 600 feet per minute.

I have found that when inks are used made of these water-sensitive resins dissolved in fast evaporating simple glycols (e.g. propylene glycol), and.the; distribution system is blanketed with dried air saturated with solvent vapor,.speeds.of 1500 feet per minute are attainable in multiple films, with a superheated, steam .drier. ,The resultant printed web is characterized by much better physicalproper'ties, particularly strength,

than paperdried at similar speedsthrough conventional gas, orgas and drum driers, where dry heat is used.

While I have shown my invention as applied to a four color web of one design, the method is applicable to other presses, including flat-bed presses, sheet fed rotary presses, multi color presses with single impression cylinders and the like, since any of these presses can be blanketed in a body of dried air. It is only necessary to fit the blanketing procedure to the particularpress.

For most printing, it will be obvious that the dried air treatment alone will provide all that is necessary, in combination with my new inks, to give suficiently high press speeds. However, the combination of dried air with saturation with solvent vapor, makes possible improvements in present day techniques in high speed publication printing.

I claim:

1. The method of web printing at speeds substantially in excess of 400 feet per minute on a typographic press with an extended distribution system, with inks which can be set by the addition of moisture thereto, which comprises printing on a web at such speeds with inks which are unprintable on the press at ordinary ambient relative humidities above about 55%, while maintaining about the distribution system of the press a body of air at a relative humidity less than that of the balance of the press room and not above 50%, and thereafter exposing the web to superheated steam outside the body of air.

2. The method of web printing at speeds of the order of 1000 feet per minute or more on a typographic press with an extended distribution system with inks which can be set by the addition of moisture thereto and which are unprintable on the press by reason of their containing solvents which are so volatile that the inksv dry on the press and which in any event are unprintable at ambient relative humidities in excess of 55%, which comprises printing at such speeds with such inks while maintaining about the distribution system of the press a body of air at a relative humidity not above 50% and containing a sufficient concentration of ink solvent vapor to retard evaporation of the ink solvent, and thereafter exposing the web to superheated steam outside the body of air.

3. The method of high speed printing on a typographic press with an extended distribution system with inks which can be set with the addition of moisture thereto, which comprises printing at a speed substantially in excess of 400 feet per minute with inks which are unprintable on the press at ordinary ambient relative humidities above 55% while maintaining about the distribution system of the press a body of air at a relative humidity less than that of the-balance of the pressroom and not above and thereafter drying the printed ink at said speed by adding moisture thereto outside the body of air.

4. The method of high speed printing on a typographic press with an extended distribution system with inks which can be set with the addition of moisture thereto, which comprises printing at a speed substantially in excess of 400 feet per minute with inks which are unprintable on the press at ordinary ambient relative humidities above while maintaining about the distribution system of the press, a body of air at a relative humidity not above 50%, and thereafter drying the printed ink by adding moisture thereto outside of body of dry air.

References Cited in the file of this patent UNITED STATES PATENTS 643,372 Cornwall Feb. 13, 1900 1,805,144 Jones May 12, 1931 1,827,530 Le Grand Oct. 13, 1931 2,063,636 Stevens et al. Dec. 8, 1936 2,063,672 Goddard Dec. 8, 1936 2,272,406 Gurwick Feb. 10, 1942 2,298,803 Morris Oct. 13, 1942 2,319,853 Durham May 25, 1943 2,395,151 Sodamka Feb. 19, 1946 2,556,262 Faeber June 21, 1951 2,574,900 Williams et a1 :Nov. 13, 1951 2,821,133 Brodie Jan. 28, 1958 2,854,924 Ault et a1. Oct. 7, 1958 OTHER REFERENCES Ellis: Printing Inks, 1940, Reinhold Pub. Co., N.Y.; only pages 475 and 476 made of record. (Copy available in Div. 17.) 

